Nouns

(n)substantiveany word or group of words functioning as a noun

Adjectives

(s)substantial, substantiveof or relating to the real nature or essential elements of something“a substantial argument”
(a)substantive, essentialdefining rights and duties as opposed to giving the rules by which rights and duties are established“substantive law”
(s)meaty, substantivebeing on topic and prompting thought“a meaty discussion”